The present invention relates generally to a contact retention assembly for an electrical connector and, more particularly, to a contact retention assembly embodying integral contact retention means.
The use of releasable electrical contacts in an electrical connector has rapidly increased due to the simplicity in replacing contacts in the field. Such replacement of contacts has obviated the necessity of replacing the entire connector assembly due to failure of a single contact. Both front and rear release retention systems have been utilized. A typical system utilizes a metal clip which is embedded in a plastic insulator for securing the contact in the connector assembly. Such an arrangement is shown in U.S. Pat. No. 3,158,424.
The disadvantages of metal clips in electrical connector assemblies are well known. A primary disadvantage is the large cost in molding or otherwise mounting the clip in the assembly. Further, in the metal clip retention arrangement, contact movement or splay may result from clip geometry and movement due to an inadequate mounting of the clip in the connector assembly. To overcome the disadvantage of metal clips in releasable contact connector assemblies, a plastic clip retention system has been used. Such arrangements are shown, for example, in U.S. Pat. Nos. 3,101,229; 3,165,369; and 3,638,165. The retention arrangements disclosed in these patents each embody a conical or cylindrical shaped retention member which surrounds the contact passage in an insulator. The contact is inserted into the passage from the rear of the insulator until the retention member snaps into a groove or behind a shoulder on the contact, limiting rearward movement of the contact in the passage. A shoulder is also required on the contact for engaging a rearwardly facing surface on the insulator to limit forward movement of the contact in the passage. An annular clearance space surrounds the retention member so that it will be free to be deflected radially outwardly when it is desired to remove the contact from the passage. This arrangement has the disadvantage, however, that the retention members are not supported sufficiently in the radial direction to provide as strong a retention force on the contacts as required for some applications. (Co-pending U.S. application Ser. No. 371,958, filed June 21, 1973, entitled, "Contact Retention Assembly," by M. J. McGhee, now) U.S. Pat. No. 3,824,523, discloses an integral contact retention arrangement in which the retention tines are surrounded by a rubber sealing grommet. This grommet, however, remains permanently in place and the contacts are inserted into and withdrawn through passages in the grommet. The retention tines are deflected radially outwardly by a special tool. The grommet deforms to accommodate this outward deflection of the tines. The grommet therefore does not provide any rigid support for the tines which would enhance the retention force on the contact.
It is the object of the present invention to provide an improved contact retention assembly having higher retention forces. It is also another feature of the invention to provide a contact retention assembly which does not require a separate shoulder on the contact to limit forward movement of the contact in the retention disc. Also, the invention permits the use of a wide variety of materials for the retention disc which is not possible with prior art integral contact retention assemblies wherein material specifications are typically very stringent.